Traveling block arrester



May 17, 1955 H. J. wooLsLAYER ETAL 2,708,565

TRAVELING BLOCK ARRESTER Filed June 23, I.1954 2 Sheets-Sheet lINVENTORS //oMER J wao/ SL/ayk.

THe/R Hna/@Mfrs 2 Sheets-Sheet 2 TRAVELING BLOCK ARRESTER H. J.WOOLSLAYER ETAL May 1'7, 1955 Filed June 23, 1954 Wires natanti'. nn 2s,19st, stan Nt. 438,653 Cxafms. (ci. zia-4414s) This invention relates toapparatus for arresting a rising traveling block before it can strikethecrown block from which it issuspen'ded in an oil well mast.

Occasionally the operator of the drawworks of an oil well drilling mastmiscalculates and allows the traveling .block to rise so high in themast that it strikes the crown block. This may cause considerable damageto the equipment as well as endanger the men at the basel of the mast,due to falling parts. It has been proposed to limit the upward travel ofthe traveling block by having the block trip an electric switch thatwill warn the drawworks operator, but such apparatus depends for itssuccess 'on the operators reaction time. Ifhe does not act, quicklyenough, the block may strike the crown anyway. Where the traveling blockis used to actuatean electrical system that opens the ignition circuitof a drawworks engine that has electrical ignition, the momentumof theengine `generally makes the reaction time too long to besafe.

It is among the objectsof this invention to provide a travelingblockarrester which is entirelyunehanical in its operation, which does notdepend on the operators reaction tirne, which cannot fail to work, whichis easily installed on new or existing oil well masts, which requires nomaintenance, and which is relatively inexpensive.

In accordance with this invention the travelingblock arrester is a shortdistance belowthe jcrown block that supports a travelingblock by theusual lines formed by a cable reeved around thesheaves in .the twoblocks. For convenience of description only, the lines will be `referredto herein as front and rear lines, `s o that .the position of thevarrester relative to the lines can be described more easily. Thearrester includes 'a -pair of normally reclining front and rear armshaving the frontend ofthe front arm and the rear end of the rear armpivotally supported on the mast on parallel horizontal axes. The armsextend from their pivots in opposite directions across all et' thelines. A snubbing member is carried by the rear end of the front arm andextends laterally across the back of the rear lines. Another snubbingmember, carried by the front end of the rear arm extends laterallyacross the front of the front lines. Means are carried by the arms whichare adapted to be engaged by the rising traveling block to swing thearms upward in order to move the snubbing members inward toward eachother and tightly against the lines between them. When this occurs, theupward movement of the traveling block will be retarded and theincreased laboring of the drawworks will indicate to the operator thatthe traveling block is too high in the mast. In effect, the arresterforms a resilient obstacle in the path of the traveling block so thatthe latter can be stopped before any damage is done.

The preferred embodiment of the invention is illustrated in theaccompanying drawings, in which: Fig. 1 is a side view of the upper endof an oil well mast, showing our traveling block arrester in snubbingposition;

Fig. 2 is a fragmentary front view of the arrester taken on the lineII-II of Fig. l; and

Fig. 3 is a horizontal section through the mast on the anni Aare spacedsubstantially equal distances` apart.

2,7%,555 ...Patented Mayr?, tsss 2 line III- III of Fig. Vl, showing thearrester in inoperative or collapsed position.

Referring to the drawings, the legs 1 and 2 of an oil wellmast, whichare referred toherein for convenience as block provided withthe usualrow of sheaves 3, behind which there is a fast s heave 5. A cableextends upward from the usual drawworks (not shown), over the fastsheave and then forward over the front sheaves. The cable `is reevedaround the, crown sheaves and the sheaves 6 in the travelthe mast, andthen is dead-ended at one lower corner of the mast. The lines connectingthe two blocks form two separate groups, a front group 3 Vand a reargroup 9, which are more or less parallel to each other.

Welded or otherwise secured to the oppositesides of the mast are a pairof horizontal channelsll, whichextend fromthe rear legs forward past thefront legs. 'EX- tending across the space between the two rear legs ofthe mast is a horizontalhollow shaft 12 which has its ends supported insockets 13 Athat are bolted to the rear legs. A similar horizontal shaft14 has its ends supported in sockets 15 that are bolted to the innerfaces of the front ends of the 'two channels 11. The two shafts areparallel to each other land `at the same level. They also are spacedequal distances from the extended center line of the well. Plvotallymounted on each of these shafts is one `end ot` an arm. One arm 17extends forward from the rear shaft and the other arm 18 extendsbackward from the ront shaft and they both extend across all ofthelines.Preferably, thereararm 1 7, which is the one mountedon the rear shaft,is formed from a pair ofparallel bars 2 0. The rear ends of the bars`are secured to sleeves 21-pivotally mounted on the rear shaft near itsopposite ends. The front ends of the bar s are rigidly connected by atu--bular snubbing member 22 which may be welded between them. Both groupsof lines are between the two bars. Thepfront `arm 18 likewise is formedfrom a pair of parallel bars 24 having their front ends secured tosleeves 25 `journaled on the front shaft at the opposite ends ofacentral collar 26 which spaces them apart. The rear ends of these barsare rigidly connected by a tubular snubbing member 27, the ends o fwhich overlie and reston the other pair of bars 20 behind the rear group9 of1ines. The other snubbing member rests on the fr ont bars 24 infront of the front group 8 of lines. The front bars are muchclosertogether than the rear bars, but all fourbars The front barspassbetween some of the lines. The lines normally dojn'ot touch any ofthe elements of the vtraveling block arrester, so that in normal andproper operation of the mast the arrester serves no purpose whatever.

if the drawworks operator inadvertently allows the traveling block torise too high in the mast and dangerously close to the crown block, thearrester will come into operation at once.

tom of the rear arm behind the center line of the well, and the frontarm carries a similar member 31 in front of that center line. The rearcross member has its ends detachably supported in tubular brackets 32welded to the bottoms of the rear bars 20, while the front cross member31 is divided into two short pieces. Each piece is rigidly mounted in abracket 33 (Fig. 1) fastened to the bottom of one of the front bars 24.There is a space or slot between the two front pieces, and their outerends are spaced from the outer or rear bars. Before the front shaft 14is inserted in the front sleeves 25 and mounted between the front endsof channels 11, the front bars24.

are inserted between the lines from the rear of the mast. The two rearlines between those bars can pass through the slot in the front crossmember 31. Likewise, before the rear shaft 12 is inserted in rearsleeves 21 and fastened to the rear legs of the mast, the rear bars 2Gare moved back across the lines from the front of the mast. At that timethe rear cross member 30 is removed so that it will not strike the frontlines and prevent the rear arm from being moved further back.

lIt will be seen in Fig. l that if the traveling block is allowed torise too high it will strike the cross members 30 and 3l carried by thearms and swing the arms upward from their dotted line position. Thiswill swing the two snubbing member 22 and 27 inward toward each otherand against the front and rear groups of lines. The higher the travelingblock rises, the closer the snubbing members will be swung together andthe more the lines will resist that movement. The snubbing action willincrease the line load materially and cause the drawworks to labor andtend to stall and thereby warn the operator that the traveling block isdangerously high in the mast. The resistance to upward movement of theblock exerted by the lines against the snubbing members is more gradualthat if a solid member were so the situation can be corrected before anydamage is done. As soon as the traveling block is lowered again, thearms drop back to their inactive reclining position and leave the blockfree to operate in the usual way.

According to the provisions of the patent statutes, we

have explained the principle of our invention and have illustrated anddescribed what we now consider to represent its best embodiment.However, we desire to have it understood that, with the scope of theappended claims, the invention may citically illustrated and described.

We claim:

l. The combination with-an oil well mast, a crown block thereon, and atraveling block in the mast suspended from the crown block by front andrear lines, of a traveling block arrester near the crown blockcomprising a pair of normally reclining front and rear arms having thefront end of the front arm and the rear end of the rear arm pivotallysupported by the mast on parallel horizontal axes, said arms extendingfrom their pivotal supports in opposite directions across all of saidlines, a snubbing member carried by the rear end of the front armextending laterally across the back of the rear lines, a snubbing membercarried by the front end of the rear arm extending laterally across thefront of the front lines, and means carried by the arms and adapted tobe engaged by the rising traveling block to swing the arms upward inorder to move said snubbing members inward toward each other and tightlyagainst the lines between them.

put in the path of the block,

be practiced otherwise than as speshafts in opposite directions 2. Atraveling block arrester in the combination recited in claim 1, in whicheach of said arms is formed from a pair of laterally spaced barsconnected together at one end by one of snubbing members.

3. The combination with an oil well mast, a crown block thereon, and atraveling block in the mast suspended from the crown block by front andrear lines, of a traveling block arrester near the crown blockcomprising a pair of normally reclining front and rear arms each formedfrom a pair of laterally spaced bars, parallel front and rear horizontalshafts rigidly supported by the mast, sleeves secured to the front endsof the front bars and to the rear ends of the rear bars and rotatablymounted on the adjacent shafts, said bars extending from said across allof said lines, a snubbing member connecting the rear ends of the frontbars and extending across the back of the rear lines, a snubbing memberconnecting the front ends of the rear bars and extending across thefront ot' the front lines, and means carried by the bars and adapted tobe engaged by the rising traveling block to swing the arms upward inorder to move said snubbing members inward toward eachother and tightlyagainst the lines between them.

4. The combination with an oil well mast, a crown block thereon, and yatraveling block in the mast suspended from the crown block by front andrear lines, of a traveling block arrester near the crown blockcomprising a pair of normally reclining front and rear armshaving thefront end of the front arm and the rear end of the rear arm pivotallysupported by the mast on parallel horizontal axes, said arms extendingfrom their pivotal supports in opposite directions across all of saidlines, a snubbing member carried by the rear end of the front armextending laterally across the back of the rear lines, a snubbing membercarried by the front end of the rear arm extending laterally across thefront of the front lines, each of said arms being formed from a pair oflaterally spaced bars connected together at one end by one of saidsnubbing members, one of the arms straddling the other one with each ofthe snubbing members resting on the reclining pair of bars attached tothe other snubbing member, and means carried by the arms and adapted tobe engaged by the rising traveling block to swing the arms upward inorder to move said snubbing members inward toward each other and tightlyagainst the lines between them.

5. lA traveling block arrester in the combination recited in claim 4, inwhich said means include a. longitudinally spaced pair of horizontalelements attached to the inner pair of bars and spaced from the outerpair of bars, and a horizontal member removably connected at its ends tothe outer bars.

No references cited.

